Re: [cobalt-users] [Maybe OT] Anti-spam measures [SCANNED]

[Jeff Lasman <blists@xxxxxxxxxxxxx>]

On Thursday 11 March 2004 08:06 am, Dave's List Addy wrote:

> On 3/11/04 9:13 AM, "Bruce Demske" wrote:
> > When you set up the gateway, is there an easy way to export valid
> > email addresses (users and aliases) from the raq's?
>
> No need to do that. We used a Debian server with Sendmail and
> MailScanner and Spamassassin.

Actually there's a very good reason to do it.  If you don't do it then 
your gateway mailserver will accept email for all addresses for the 
domain, even undeliverable ones.  It will attempt to deliver 
undeliverable ones, find it can't, and then try to return them.

In the case of virii, trying to return them will result in lots of 
innocent bystanders getting bombarded with returns for virii they 
didn't send.

In the case of spam, trying to return them will result in mail being 
returned to the wrong place, mail getting "stuck" in the queue, or mail 
being returned to a server that won't accept it.  In the worst case it 
can result in mail-loops.

We use exim on our gateway system and configure it to check the address 
at the final machine before deciding to accept or reject the mail.

Even this isn't foolproof, but it helps.

Then we run a cron job daily to remove "stuck" email over four days old 
from the outgoing queue.

Jeff
-- 
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Professional Internet Services & Support / Consulting / Colocation
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